What Are Good Ranges for Fill Water?

[KevMo]

We are in the very early stages of talking to PBs about building a pool. I want to be able to use my irrigation well to fill the pool. The water supplied to the house from the local water company in my area is very expensive.

I am glad I found this site. I have been reading a lot. I ordered the TF-Pro test kit with pH meter and tested my well water twice. I got the following values:
pH: 7.2
CH: 70
TA: 220

Are these levels going to be alright to use as fill for a plaster pool? Any particular advance planning I should do?

 

[Dirk]

Understood that you'll be filling your pool from the well. What about subsequent topping off (from evaporation): city or well water?

pH is a non issue.

So is CH, for the most part. Yours is relatively low, but that's OK. After the initial fill, you'll need to add CH manually one time, and that's easy, but for subsequent topping off, that low CH will be a good thing.

So the issue is the TA. 220 is high. You can get it back down after the initial fill, but it'll be an issue for topping off. You'll likely see continuous pH rise (driven by the high TA). I have the same issue with my city water. I use an automated acid dosing system to compensate for the high TA (to keep my pH in range).

Other than that, you could consider connecting your pool's fill supply (or auto-filler) to a water softener. That will minimize your CH rise. CH collects in a pool over time, and eventually will rise above the recommended level, even with CH70 fill water. A softener would drastically slow that CH rise. 70 isn't bad though, you can handle that by periodically replacing pool water, if you don't want to go with a softener. If you had plans for one for your house, you can use that softener. That's what I do. Between that and the acid dispenser, my high CH and TA fill water is a non issue.

And of course you can wait on the acid system and/or water softener, and run your pool without them for a year or more, and see how it goes. After that, if you find battling with the TA a hassle, or you see your CH rising too fast, then you can later add the appropriate gizmo to compensate.

If you'll be topping off with city water, then you'll need to post those numbers to get appropriate advice for that water source.

By the way, welcome to TFP!

 

[mgtfp]

What Dirk said.

In areas with lots of rain (where you have to drain water (containing calcium) to make room for more rain (containing no calcium), CH can drop over time, when the fill water CH is sufficiently low.

My fill water has CH 30 (or 40, can't remember exactly).

During summer, when having to top up evaporated water with fill water, my CH creeps slowly up.

During Winter, where we get quite a bit of rain, my CH drops again.

On average, it keeps dropping, so I have to add some calcium every few years. But I assume, you don't get that much rain in TX.

A pool cover can help to minimise evaporation and slow CH and TA rise down.

 

[KevMo]

My plan is to use my well for topping off. I tested the water supply to the house and got very similar numbers with a higher pH.
pH: 7.5
CH: 60
TA: 200

We get about 50" of rain annually in Houston but it tends to come in bunches. The summers are hot. The pool we had at a previous home in the Houston had a lot of evaporation during the summer.

@Dirk , what is the automated acid dosing system you use?

 

[Dirk]

My plan is to use my well for topping off. I tested the water supply to the house and got very similar numbers with a higher pH.
pH: 7.5
CH: 60
TA: 200

We get about 50" of rain annually in Houston but it tends to come in bunches. The summers are hot. The pool we had at a previous home in the Houston had a lot of evaporation during the summer.

@Dirk , what is the automated acid dosing system you use?

With that much rain, your CH70 fill water will likely be easy to manage, and would make a softener unnecessary. You'll probably need to add calcium periodically, not drain it off. But our testing/dosing methods here at TFP make managing all the pool chem's a breeze.

I have a 100% Pentair pad. So I use a Pentair IntellipH (IpH). It installs as a companion to the Pentair IntelliChlor (IC), and they are well designed to work together. The IC must be present for the IpH to work, the IpH cannot be installed stand-alone (not without DIY modifying it, which is possible). For example, the IpH stops the IC from dispensing chlorine while the IpH is dispensing acid. The IpH also used the IC's built in flow and temperature sensors: the IpH won't dispense if the IC determines flow is too low, or stopped altogether, and the IpH won't dispense when the IC is down for the winter (when the water is too cold). That latter "feature" is actually a "con" for the IpH, and I modified mine to dispense year-round, even when my IC is not running, but that's a DIY kluge I developed, not something available with the stock setup. The IpH piggybacks off the IC's power supply, which is the primary reason it isn't stand-alone. But this is a good thing: if the IC is wired correctly to only run when the pump is running, then the IpH gets the same safety-feature benefit (of not being able to dispense when the pump is off).

The IpH tank is particularly well designed, very easy and safe to fill, bolts to the pad, holds about four gallons, and has a venting system that minimizes the effects of acid fumes on your pool equipment. The acid pump is part of the tank, so it makes for a streamlined all-in-one system on the pad.

Full disclosure: the IpH unfortunately has a known "bug" that can cause both the IC and the IpH to stop working. It's a problem with the circuit board that Pentair has yet to address. Pentair honors the warranty for this problem, and there is a relatively simple DIY preventative fix for this, if you're at all handy. It doesn't happen to all setups, and happens more often in systems that have the bigger ICs (IC40 and IC60). The problem is related to the amount of current the IC is pulling through the IpH. Not a stellar "feature," for sure, but it wouldn't keep me from getting another one, or recommending one to others, because their is a work-around fix.

Stenner also makes acid dispensing systems, as does Hayward. Never having used either, I can't detail their pros and cons. The IpH definitely has several safety features that would be challenging if not impossible to recreate with a Stenner system. I don't know if the Hayward system has any of the same safety features or not.